JPH0129954Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention provides a thin push switch, and particularly relates to a push switch used in a so-called keyboard switch in which a plurality of switches are arranged on the same plane.

A conventional push switch for a slim keyboard switch was as follows. The structure is shown in FIG. 1, and 1 is a printed circuit board on which a conductive pattern 2 as shown in FIG. 2 is formed and has a contact area 2a. In FIG. 1, 3 is a conductive rubber that comes into contact with and separates from the contact area 2a,
This conductive rubber 3 is fixed to the rubber inversion body 4 by means such as pressure bonding. The drawbacks of such a keyboard switch in which a plurality of switch sections are arranged in a panel shape are as follows.

First, the reversal feel is gradual and it is difficult to get a clear sense of moderation. In addition, the stroke (corresponding to the gap between the printed circuit board 1 and the conductive rubber 3) is required to be about 1 mm, and the push part is also somewhat thick, so there is a limit to how thin it can be made.

Therefore, a configuration using a metal diaphragm has been adopted once or twice, but this requires means such as connecting the fixed contact metal member to a printed circuit board, and there are few practical examples.

Therefore, the present invention aims to provide a push switch for a keyboard that does not have the drawbacks of the above two conventional examples.

Hereinafter, one embodiment of the present invention will be explained in Figures 3 to 6.
This will be explained with figures. First, in Fig. 3, 5 is a substrate with fixed contacts made of conductive foil, 6 is an inverted diaphragm made of a pressed metal strip that also serves as a movable contact, and 7 is a surface panel made of rubber.
It has a concave shape along the convex surface of the inversion diaphragm 6 to maintain a flat surface. 8
is a protrusion provided on the panel 7 for preventing movement of the inversion diaphragm 6, and is fitted into a hole 9 formed in the substrate 5. Reference numeral 10 denotes a relief hole for letting the air in the space 11 escape to the outside through the hole 9 when the reversing diaphragm 6 is in operation, and also serves to allow air to enter when the inversion diaphragm 6 is in the OFF operation. Then, by pressing the front panel 7 and reversing the reversing diaphragm 6, the fixed contacts provided on the substrate 5 are made conductive, thereby forming a switch.

FIG. 4 shows the above-mentioned inverted diaphragm 6, which is made of a spring metal strip such as phosphor bronze, and the cross-shaped hole 12 formed in the center contributes to the stability of the contact.
FIG. 5 shows an example of a pattern of conductive foils that serve as fixed contacts provided on the substrate 5. Due to multilayer printing, the conductive foils 13 and 14 are electrically insulated from each other.

13a is a lead portion of the conductive foil 13. FIG. 6 is an explanatory diagram of multilayer printing of the substrate 5, and the thickness direction is emphasized. In FIG. 6, reference numeral 13 denotes the conductive foil which serves as the central contact, and is the first layer printed simultaneously with the lead portion 13a. Reference numeral 14 designates the conductive foil printed as a second layer, which is electrically insulated from the conductive foil 13 through an insulating layer 15 of a resist made of an organic insulating material, and serves as a peripheral contact point. Reference numeral 16 denotes a dummy conductive foil provided by printing the first layer as a means for making the height of the conductive foil 14 uniform. This is to avoid damaging the conductive foil 14 during operation, thereby preventing conduction from occurring between the conductive foil 13 and the conductive foil 13.

Then, the conductive foil 13,1 is printed as the first layer.
Copper foil for 6, phenol plate or polyimide for substrate 5,
So-called printed circuit boards such as epoxy and polyester can be used. Furthermore, if a multilayer printed circuit board is used, all layers can be formed of copper foil. Furthermore, plating only the contact area has the effect of increasing contact life, and it is also possible to provide part or all of each conductive layer by baking a paste of carbon, silver, or other conductive material. be. Note that it is also possible to use a metal inverted diaphragm plated.

As described above, the switch of the present invention includes a conductive inverted diaphragm, a peripheral contact and a central contact formed on a substrate using conductive foil, and a central contact provided on the lower surface of the peripheral contact. The structure includes a dummy conductive foil of the same layer as the conductive foil, and an insulating layer provided between the conductive foils of the peripheral contact and the center contact and between the peripheral contact and the dummy conductive foil. The height of the conductive foil on the peripheral contacts can be made uniform, ensuring reliability by preventing the reversing diaphragm from tilting and damaging the peripheral contacts and causing conduction with the central contact when the reversing diaphragm operates. It is possible to provide a push switch that is extremely thin and has a high click feel, and a keyboard switch using the push switch, which can be used to miniaturize devices.

[Brief explanation of the drawing]

Figure 1 is a cross-sectional view of a conventional push switch.
Fig. 2 is a diagram illustrating the pattern of the circuit board constituting the switch, Fig. 3 is a sectional view showing an embodiment of the push switch according to the present invention, and Fig. 4 is a perspective view of the inverted diaphragm constituting the switch. Figure, 5th
The figure is a diagram illustrating a conductive pattern on a substrate constituting the switch, and FIG. 6 is a sectional view similarly illustrating a specific structure of the conductive pattern on the substrate. 5...Substrate, 6...Inverted diaphragm, 7...
Surface panel, 13... Conductive foil (center contact), 1
4... Conductive foil (peripheral contact), 15... Insulating layer,
16...Dummy conductive foil.

Claims (1)

[Claims for Utility Model Registration] (1) A conductive inverted diaphragm, a peripheral contact and a central contact formed on a substrate using conductive foil, and the central part provided on the lower surface of the peripheral contact. A dummy conductive foil of the same layer as the conductive foil of the contact,
an insulating layer provided between the conductive foils of the peripheral contact and the center contact and between the peripheral contact and the dummy conductive foil, and the inverted diaphragm maintains conduction between the center contact and the peripheral contact. A push switch configured by the reversal action of. (2) The push switch according to claim 1, which is a utility model, and includes a surface panel having a concave shape along the convex surface of the inverted diaphragm.